July 11, 2022

Binary tree right side view

This problem asked us to return the list of the nodes when we look it from the right side. That means, if we traverse the whole tree with BFS, we will see the right side node of the tree in each...

Read

July 11, 2022

Max area of island

This is a classing grid graph problem. We will iterate through each row and column, when we find a new land, we will then expand the area of land sorrounding. We can use BFS or DFS to do that. I will...

Read

July 10, 2022

Contains duplicate

We are given a list of integers. We have to find out whether we have any duplicate or not. We can store the elements in a hashset while iterating through the list. We the item is already present in...

Read

July 10, 2022

Two sum

This problem has very clear statement. It will have a list of integer and a target integer. We should return the 2 indeces of the numbers that adds up to the target. It is guranteed that we will have...

Read